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It is a challenge to accurately assess pancreatic cystic lesions (PCLs) and determine their risk. We compared the yield of tissue acquired with endoscopic ultrasound (EUS)-guided microforceps (through the needle tissue biopsy [TTNB]) with that of samples collected by EUS-guided fine-needle-aspiration (EUS-FNA), and the accuracy of analyses of each sample type in the diagnosis of mucinous PCLs. We performed a prospective open-label study of 114 consecutive adults (56.1% women; mean age, 64.2 y) undergoing EUS-FNA evaluation of PCLs (mean size, 35 mm) at 7 centers, from June 20, 2016, through August 31, 2018. Samples were collected from each cyst by FNA and microforceps; samples collected by FNA were analyzed by cytology and samples collected by TTNB were analyzed by histology. Acquisition yield was defined as the percentage of specimens collected that were adequate for cytologic or histologic analysis. Diagnoses of mucinous cysts were made based on identification of pancreatic mucinous epithelium by cytology analysis of FNA samples or histologic analysis of TTNB samples. Surgical specimens were used as the reference standard when available. The EUS-guided microforceps were successfully inserted into 97.4% (111 of 114) of PCLs. Tissue acquisition yield was significantly higher with TTNB (95 of 114; 83.3%) than FNA (43 of 114; 37.7%) (P <.001). Sixty-one PCLs were determined to be mucinous based on TTNB analysis (53.5%) vs 11 with FNA analysis (9.6%) (P <.001). Among PCLs categorized as equivocal, based on the level of carcinoembryonic antigen, TTNB analysis found 50% (41 of 82) to be mucinous and FNA analysis found 8.5% (7 of 82) to be mucinous (P <.001). Findings from analyses of samples collected by TTNB were 100% concordant with findings from histologic analysis of surgical specimens (14 of 14), whereas only 3 of 14 findings from analysis of samples collected by FNA were in agreement with findings from surgical specimens (21.4%) (P <.001). Four of 5 mucinous PCLs with advanced neoplasia (80%) were detected with TTNB compared with none with FNA (P =.04). Self-limited intracystic bleeding occurred in 7 patients (6.1%), and acute pancreatitis in 6 patients (5.3%). In a multicenter prospective study of patients undergoing EUS-FNA for evaluation of PCLs, we found TTNB collection of tissues for histologic analysis to be safe and feasible, with an acquisition yield of 83.3%. Histologic analysis of samples collected by TTNB identified a larger proportion of mucinous PCLs compared with cytologic analysis of samples collected by FNA—even among samples categorized as equivocal, based on the level of carcinoembryonic antigen. More samples collected by TTNB than FNA were found to have advanced neoplasia. Clinicaltrials.gov no: NCT02979509. [ABSTRACT FROM AUTHOR]

Background & Aims Despite the widespread use of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) to sample pancreatic lesions and the standardization of pancreaticobiliary cytopathologic nomenclature, there are few data on inter-observer agreement among cytopathologists evaluating pancreatic cytologic specimens obtained by EUS-FNA. We developed a scoring system to assess agreement among cytopathologists in overall diagnosis and quantitative and qualitative parameters, and evaluated factors associated with agreement. Methods We performed a prospective study to validate results from our pilot study that demonstrated moderate to substantial inter-observer agreement among cytopathologists for the final cytologic diagnosis. In the first phase, 3 cytopathologists refined criteria for assessment of quantity and quality measures. During phase 2, EUS-FNA specimens of solid pancreatic lesions from 46 patients were evaluated by 11 cytopathologists at 5 tertiary care centers using a standardized scoring tool. Individual quantitative and qualitative measures were scored and an overall cytologic diagnosis was determined. Clinical and EUS parameters were assessed as predictors of unanimous agreement. Inter-observer agreement (IOA) was calculated using multi-rater kappa (κ) statistics and a logistic regression model was created to identify factors associated with unanimous agreement. Results The IOA for final diagnoses, based on cytologic analysis, was moderate (κ = 0.56; 95% CI, 0.43–0.70). Kappa values did not increase when categories of suspicious for malignancy, malignant, and neoplasm were combined. IOA was slight to moderate for individual quantitative (κ = 0.007; 95% CI, –0.03 to –0.04) and qualitative parameters (κ = 0.5; 95% CI, 0.47–0.53). Jaundice was the only factor associated with agreement among all cytopathologists on multivariate analysis (odds ratio for unanimous agreement, 5.3; 95% CI, 1.1–26.89). Conclusions There is a suboptimal level of agreement among cytopathologists in the diagnosis of malignancy based on analysis of EUS-FNA specimens obtained from solid pancreatic masses. Strategies are needed to refine the cytologic criteria for diagnosis of malignancy and enhance tissue acquisition techniques to improve diagnostic reproducibility among cytopathologists. [ABSTRACT FROM AUTHOR]